1. Field
The disclosure relates, in general, to a flat panel display and a driving method thereof, and in particular, to a flat panel display configurable with a reduced bezel width and a driving method thereof.
2. Related Art
Referring to FIG. 1, a circuit diagram of a shift register 100 of a gate driving unit of a conventional flat panel display is shown. The shift register 100 includes transistors T10 through T70, outputs an output signal Out′_n at an output terminal OUT thereof, and receives clock signals C1′, C3′ as well as an output signal Out′_n+2 from another shift register. In the shift register 100, when the drain terminals of the first transistor T10 and the third transistor T30 receive a very high revel bias voltage, such as 16V, the node P10 will be biased at the very high level bias voltage.
However, the high level bias voltage at the node P10 will excessively bias the gates of the second transistor T20 and the sixth transistor T60. As a result, the respective threshold voltages of the second transistor T20 and the sixth transistor T60 will increase to a considerable level with time. As the threshold voltage increases, the second transistor T20 is weakened in discharging electricity to the node P20, and more time is required to turn off the fifth transistor T50. Consequently, the scan line which the output terminal OUT belongs to will receive erroneous data, and the gate driving unit will cause erroneous action.
To solve the above problem, an additional DC power source is provided to the drain terminal of the third transistor T30 to provide an additional work voltage Vdd′ smaller than the original high level bias voltage, so as to reduce the gate bias voltages of the second transistor T20 and the sixth transistor T60. However, an additional circuit is required to provide the DC power source, thereby increasing the overall cost. Moreover, a wide power line should be attached to the edge of the glass substrate for power transmission from the additional DC power source. Such wide power line will increase the bezel width of the glass substrate.